ISO 8601 allows +hh and -hh

[Deleted user]

Thanks for the handy software! ISO 8601 allows +hh and -hh for time offsets. Right now the time in New York city is approximately 20:52 -05. If +hh and -hh could be added I'd appreciate it. Thanks for reading.

[KEIII]

The extension itself does't do date format, but uses strftime() under the hood. So you can use any supported format https://developer.gnome.org/glib/stable/glib-GDateTime.html#g-date-time-format
It's may be helpful:

%z: the time zone as an offset from UTC (+hhmm)
%:z: the time zone as an offset from UTC (+hh:mm). This is a gnulib strftime() extension. Since: 2.38
%::z: the time zone as an offset from UTC (+hh:mm:ss). This is a gnulib strftime() extension. Since: 2.38
%:::z: the time zone as an offset from UTC, with : to necessary precision (e.g., -04, +05:30). This is a gnulib strftime() extension. Since: 2.38

[KEIII]

It seem nothing to do here.